Glassy Dynamics of Protein Folding

TL;DR

This study models protein folding dynamics using a simplified coarse-grained approach, revealing stretched exponential relaxation and universal energy landscape features consistent with experimental observations.

Contribution

Introduces a coarse-grained protein folding model demonstrating universal relaxation behavior and energy landscape features across different dynamics.

Findings

Relaxation follows a stretched exponential with exponent ~1/4.

Correlation functions share the same functional form as experimental data.

Energy landscape exhibits universal features over a wide energy range.

Abstract

A coarse grained model of a random polypeptide chain, with only discrete torsional degrees of freedom and Hookean springs connecting pairs of hydrophobic residues is shown to display stretched exponential relaxation under Metropolis dynamics at low temperatures with the exponent $\beta\simeq 1/4$, in agreement with the best experimental results. The time dependent correlation functions for fluctuations about the native state, computed in the Gaussian approximation for real proteins, have also been found to have the same functional form. Our results indicate that the energy landscape exhibits universal features over a very large range of energies and is relatively independent of the specific dynamics.